Need threaded PVC plumbing advice.

[tonyespinoza]

What do you guys think is the safest protection against leaks when using threaded Schedule 80 PVC fittings? Teflon tape, silicone sealant, or something else?

Any other tips for the best possible, leak-proof connection?

(Or is the answer to avoid threading as much as possible!?)

Thanks for any sage advice!

 

[DEERE G]

I use tape in the thd. connections I have. Nothing wrong with threads. Using unions is a good idea to be able to unthread things if needed. IMO

 

[THolleyH46]

Tapes fine, place sump under holes and watch for leaks.

 

[chrismunn]

if your not comfortable using teflon tape alone, then you can also use teflon paste over the tape.

http://www.kingssupply.com/item36.htm

 

[Esquare]

Teflon Tape and lots of it, normally 10 turns for me.

I like to use threaded fittings and unions wherever possible, as whenever I see well enough, I have to start poking at it until it isn’t well enough any more.

 

[jdieck]

I use two or three layers of teflon tape on the male thread and then a very small amount of teflon paste on top of it this way any excess paste will be left out of the pipe while threading.
Some molded threads have the mold flash off line a bit missaligned, the paste helps sealing that area.

 

[tonyespinoza]

perfect - just the advice i was hoping for!

jdieck - not sure if i understand the following, "then a very small amount of teflon paston on top of it this way any excess paste will be left out of the pipe while threading." i'm certain i'm brain dead at this point (got a 3 week old newborn at home)... do you just mean that you put the paste on the tape with the male threads rather than on the female end?

 

[jdieck]

<a href=showthread.php?s=&postid=14020872#post14020872 target=_blank>Originally posted</a> by tonyespinoza
perfect - just the advice i was hoping for!

jdieck - not sure if i understand the following, "then a very small amount of teflon paste on top of it this way any excess paste will be left out of the pipe while threading." i'm certain i'm brain dead at this point (got a 3 week old newborn at home)... do you just mean that you put the paste on the tape with the male threads rather than on the female end?

Means do not apply paste to the female connection or the excess paste will end up inside the pipe after threading in the male.
Apply only to the male thread.

Use two or three layers (wraps) of Teflon tape. More than that will be pushed out while threading and tightening and may force the female connector to expand and crack due to the thread being tapered (Conical) the more your tighten the more the female side will deform sideways.

Because of the quality of the thread is not always perfect a small amount of TFE paste applied on top of the layered tape will help seal any deformities in the thread.

 

[tonyespinoza]

makes a lot of sense. thanks for the clarification.

 

[Mako]

I hate using paste, so very messy. Teflon tape alone has always worked out well for me. One suggestion I would make is to invest in a strap wrench, or two. Worth their weight in gold when working with threaded fittings.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=14020723#post14020723 target=_blank>Originally posted</a> by Esquare
Teflon Tape and lots of it, normally 10 turns for me.

I like to use threaded fittings and unions wherever possible, as whenever I see well enough, I have to start poking at it until it isn’t well enough any more.

The extra tape can easily split the fittings. It is much safer and more effective to use the teflon paste

 

[BeanAnimal]

<a href=showthread.php?s=&postid=14020757#post14020757 target=_blank>Originally posted</a> by jdieck
I use two or three layers of teflon tape on the male thread and then a very small amount of teflon paste on top of it this way any excess paste will be left out of the pipe while threading.
Some molded threads have the mold flash off line a bit missaligned, the paste helps sealing that area.

I have found that the tape only servers to create a possible problem with threaded PVC. The paste alone is enough to create a leak free joint. YMMV

 

[Esquare]

<a href=showthread.php?s=&postid=14022247#post14022247 target=_blank>Originally posted</a> by BeanAnimal
The extra tape can easily split the fittings. It is much safer and more effective to use the teflon paste

Thanks for the advice. I was always afraid to use the paste in case it reacted negatively with the system. Any advice on which paste and how long it needs to cure?

 

[jdieck]

<a href=showthread.php?s=&postid=14022954#post14022954 target=_blank>Originally posted</a> by Esquare
Thanks for the advice. I was always afraid to use the paste in case it reacted negatively with the system. Any advice on which paste and how long it needs to cure?

Any Teflon based paste without solvents or organics will do. Remember to apply paste only to the male conector.

Bean:
The reason I use some tape in addition to the paste is because I have found it will be easier to disconect later on but agree that paste alone will work well.

 

[tonyespinoza]

thanks everyone --- this has been a huge help!

 

[AZDesertRat]

Try LaCo Plasto Joint thread sealants designed specifically for PVC. I think you wil be thrilled with the results. It's all I have used since the 1980s and I will never go back to teflon tape of pastes either one.

http://www.laco.com/productDetail.aspx?ProductID=121

 

[sailoracu2]

teflon paste, brush it on the threads and tighten, clean off. You can buy it at HD or Lowes, works great.